Telescopic joint control line system

Abstract

A telescopic joint for an upper end of an offshore drilling riser is installed and controlled remotely. The telescopic joint has inner and outer telescoping barrels. A mandrel is located on the lower end of the outer barrel, the mandrel landing within a support ring which is supported by constant tension cables extending from the vessel. Control fluid passages are located in the mandrel for registering with control fluid passages in the support ring. Permanent control fluid lines extend between various points of the outer barrel and the mandrel. Control fluid hoses connect the support ring to the vessel. Fluid communication is achieved once the telescopic joint is oriented and landed in the support ring.

I claim: 
     
       1. A telescopic joint assembly for use with a riser extending between a subsea wellhead and a vessel, comprising in combination: an outer barrel;   an inner barrel carded within the outer barrel for vertical movement relative to the outer barrel due to wave movement;   a mandrel on a lower end of the outer barrel and adapted to secure to the upper end of a riser, the mandrel having a circumferential exterior wall;   a plurality of control fluid passages in the mandrel, each having an inlet at the exterior wall and an outlet located above the inlet;   a plurality of control fluid lines connected between the outlets of the control fluid passages and the outer barrel for supplying control fluids to the outer barrel; and   a support ring adapted to be suspended from the vessel and having a bore in which the mandrel lands to provide support for the upper end of the riser, the support ring having a plurality of control fluid passages which are adapted to be connected to a plurality of control fluid hoses extending from the vessel, the control fluid passages of the support ring each having an outlet in the bore which mates with one of the inlets in the mandrel to supply control fluid to the outer barrel.   
     
     
       2. The telescopic joint assembly according to claim 1 further comprising: a packer carried by the outer barrel, having a retracted position and an energized position for sealingly engaging the inner barrel; and wherein   one of the control fluid lines supplies one of the control fluids to the packer to cause it to move to the energized position.   
     
     
       3. The telescopic joint assembly according to claim 1 further comprising: a pneumatically actuated packer carded by the outer barrel, having a retracted position and an energized position for sealingly engaging the inner barrel;   a hydraulically actuated packer carried by the outer barrel, having a retracted position and an energized position for sealingly engaging the inner barrel; wherein   one of the control fluid lines is adapted to supply pressurized air as one of the control fluids to the pneumatically actuated packer to cause it to move to the energized position; and   another one of the control fluid lines is adapted to supply hydraulic fluid as one of the control fluids to the hydraulically actuated packer to cause it to move to the energized position.   
     
     
       4. The telescopic joint assembly according to claim 1, wherein one of the control fluid lines is adapted to supply a cooling liquid as one of the control fluids to an interface between the inner and outer barrels. 
     
     
       5. The telescopic joint assembly according to claim 1 further comprising: a locking member mounted to the outer barrel, having a released position and an engaged position in engagement with the inner barrel to selectively prevent axial movement of the inner and outer barrels relative to each other; and   one of the control fluid lines leads to the locking member and is adapted to supply one of the control fluids to the locking member to move it between the released and engaged positions.   
     
     
       6. The telescopic joint assembly according to claim 1, further comprising: at least one receptacle on the exterior wall of the mandrel;   at least one stab mounted to the support ring for movement from a retracted position to an extended position in engagement with the receptacle; and wherein   the inlets of a plurality of the control fluid passages of the mandrel are within the receptacle; and   the outlets of a plurality of the control fluid passages of the support ring are located on the stab.   
     
     
       7. A telescopic joint assembly for use with a riser extending between a subsea wellhead and a vessel, comprising in combination: an outer barrel;   an inner barrel carried telescopingly within the outer barrel, having an upper end connected to a conduit which extends upward for connection to the vessel;   a packer mounted to the outer barrel, having a retracted position and an energized position for sealing against the inner barrel;   a locking member mounted to the outer barrel, having a released position and an engaged position in engagement with the inner barrel to selectively prevent telescoping movement of the inner barrel relative to the outer barrel;   a mandrel on a lower end of the outer barrel and which is adapted to secure to the upper end of the riser, the mandrel having a circumferential exterior wall;   a packer passage having an inlet in the wall and an outlet located above the inlet of the packer passage;   a locking member passage having an inlet in the wall and an outlet located above the inlet of the locking member passage;   a packer fluid line connected between the packer and the outlet of the packer passage exterior of the outer barrel;   a locking member fluid line connected between the locking member and the outlet of the locking member passage exterior of the outer barrel;   a support ring adapted to be suspended from the vessel and having a bore which receives the exterior wall of the mandrel to provide support for the upper end of the riser;   the support ring having a packer passage which has an inlet adapted to be connected to a packer fluid supply hose extending from the vessel and an outlet in the bore which mates with the inlet of the packer passage in the mandrel to supply fluid to the packer to move it between the retracted and engaged positions; and   the support ring having a locking passage which has an inlet adapted to be connected to a locking fluid supply hose extending from the vessel and an outlet in the bore which mates with the inlet of the locking member passage in the mandrel to supply fluid to the locking member to move it between the released and engaged positions.   
     
     
       8. The telescopic joint assembly according to claim 7, wherein each of the inlets of the mandrel is located within a receptacle, and each of the outlets of the support ring comprises: a fluid actuated stab which inserts into one of the receptacles after the mandrel has located within the support ring.   
     
     
       9. The telescopic joint assembly according to claim 7 wherein the fluid which moves the packer to the engaged position is hydraulic fluid, and wherein the telescopic joint further comprises: a pneumatically actuated packer carried by the outer barrel, having a retracted position and an energized position for sealingly engaging the inner barrel;   a pneumatic passage in the mandrel, having an inlet in the wall and an outlet located above the inlet of the pneumatic passage;   a pneumatic line connected between the pneumatic packer and the outlet of the pneumatic passage exterior of the outer barrel; and   a pneumatic passage in the support ring which has an inlet adapted to be connected to a pneumatic supply hose extending from the vessel and an outlet in the bore which mates with the inlet of the pneumatic passage in the mandrel to supply air pressure to the pneumatic packer to move it between the retracted and engaged positions.   
     
     
       10. The telescopic joint assembly according to claim 7, further comprising: a coolant fluid passage in the mandrel, having an inlet in the exterior wall and an outlet located above the inlet of the coolant fluid passage;   a coolant fluid line extending exterior of the outer barrel from an interface between the inner and outer barrels to the outer of the coolant fluid passage;   a coolant fluid passage in the support ting having an inlet adapted to be connected to a coolant fluid supply hose extending from the vessel and having an outlet in the bore which mates with the inlet of the coolant fluid passage in the mandrel to supply cooling fluid to the interface.   
     
     
       11. A method for installing and operating a telescopic joint for a riser extending between a subsea wellhead and a vessel, the telescopic joint having an outer barrel, an inner barrel carried telescopingly within the outer barrel and connected to a conduit extending upward into engagement with the vessel, a mandrel on a lower end of the outer barrel which secures to the upper end of the riser, the mandrel having a circumferential exterior wall and adapted to land in a support ring suspended from the vessel which has a bore for receiving the exterior wall of the mandrel to provide support for the upper end of the riser, the method comprising:   (a) providing a plurality of control fluid passages in the mandrel, each having an inlet at the exterior wall and an outer located above the inlet;   (b) connecting a plurality of control fluid lines between the outlets of the control fluid passages and the outer barrel;   (c) providing a plurality of control fluid passages in the support ring and connecting them to a plurality of control fluid hoses extending from the vessel, the control fluid passages of the support ring each having an outlet in the bore;   (d) connecting the mandrel to an upper end of the riser and lowering the mandrel into the support ring with the outlets of the control fluid passages in the support ting oriented with the inlets of the control fluid passages in the mandrel; then   (e) supplying control fluid through the control fluid hoses to control the telescopic joint.   
     
     
       12. The method according to claim 11 wherein step (b) comprises connecting one of the control fluid lines to a packer carried by the outer barrel; and step (e) comprises supplying a control fluid through one of the control fluid hoses to the packer to cause it to sealingly engage the inner barrel.   
     
     
       13. The method according to claim 11 wherein step (b) comprises connecting one of the control fluid lines to a pneumatic packer carried by the outer barrel and another one of the control fluid lines to a hydraulic packer carried by the outer barrel; and step (e) comprises supplying pressurized air as one of the control fluids through one of the control fluid hoses to the pneumatic packer to cause it to sealingly engage the inner barrel, and supplying pressurized hydraulic fluid as another one of the control fluids through another one of the control fluid hoses to the hydraulic packer to cause it to sealingly engage the inner barrel.   
     
     
       14. The method according to claim 11, wherein step (b) comprises connecting one of the control fluid lines to an interface between the inner and outer barrels; and step (e) comprises supplying a cooling liquid as one of the control fluids through one of the control fluid hoses to the interface between the inner and outer barrels.   
     
     
       15. The method according to claim 11, wherein step (b) comprises connecting one of the control fluid lines to a locking member mounted to the outer barrel; and step (e) comprises supplying hydraulic fluid pressure as one of the control fluids through one of the control fluid hoses to the locking member to lock the inner and outer barrels together.